WASHINGTON – Twice burned, Republicans are treading carefully around tea party groups as they pursue a Senate majority that slipped through their fingers in 2010 and 2012.

"You'd have to be an idiot not to prepare" for primary election challenges from the right, no matter the state, says Rob Jesmer, who was executive director of the GOP Senate campaign committee when flawed, conservative candidates captured primaries, only to lose winnable races in the fall.

While incumbents work to ward off or repel challenges from within their party, a Republican tempest already is flaring in Georgia, where GOP Sen. Saxby Chambliss is stepping down. Party officials also look apprehensively toward Iowa, where Sen. Tom Harkin's decision to retire down opens up a seat long in Democratic hands.

The developments come at a time the Republican Party nationally is involved in a well-chronicled period of introspection after failing to win the White House last fall. President Barack Obama's support reached 53 percent among women who cast ballots, 60 percent among voters under 30, some 71 percent among Hispanics and 93 percent among blacks. Numerous officials have said the party must find a way to broaden its appeal rather than continue to steer rightward.

Brad Dayspring, a spokesman for Republicans, said consternation about a replay of recent politically damaging primaries "at least for the moment, doesn't seem to be an issue" for the GOP. Sen. Jerry Moran of Kansas, who chairs the campaign committee, declined a request for an interview.

Yet the divisions that pit the party establishment against insurgents and self-styled grass-roots groups show no signs of abating.

Karl Rove, a prominent strategist with deep ties to the Republican establishment, recently disclosed creation of a Conservative Victory Fund with the stated goal of backing electable conservatives in party primaries.

But when Rep. Tom Price of Georgia, a longtime conservative and possible Senate contender, was quoted in the National Review as saying he didn't oppose the objectives espoused by Rove's group, he drew a slap from a rival organization with close tea party ties.

"The Republican establishment is becoming increasingly hostile to the conservative movement, and Congressman Price should openly and aggressively oppose their efforts, not defend them," blogged Matt Hoskins, head of the Senate Conservatives Fund, an organization founded by former South Carolina Sen. Jim DeMint.

Price's office declined comment.

Steven Law, head of the Conservative Victory Fund, said it was too early to predict which races it would become involved in. He said the organization hopes to "work with other groups that share that mission to see if we can ensure more rigorous evaluation of candidates, find consensus where possible and perhaps most importantly prevent the Democrats from picking our nominees for us."

Incumbent Republicans seem eager to avoid antagonizing groups that have helped elect tea party favorites such as Sens. Mike Lee in Utah, Rand Paul in Kentucky, Marco Rubio in Florida and Ted Cruz in Texas in recent years.

Even before the beginning of the year, the party's Senate leader, Mitch McConnell of Kentucky, hired the campaign manager who guided Paul to his establishment-upending victory in 2010.

The party's second-ranking leader, Sen. John Cornyn of Texas, was one of only three Senate Republicans to oppose John Kerry's confirmation as secretary of state. He has said he expects a primary challenge and Democrats recently accused him of being on "Cruz control," as he seeks a new term.

Megan Mitchell, a spokeswoman for Cornyn disputed the claim while stressing the second-term lawmaker "is proud to have Ted Cruz in the Senate."

Lindsey Graham of South Carolina, a veteran senator with an independent streak, has been at the forefront of efforts to derail several of Obama's high-level nominees. He is preparing to face voters in a state where the tea party has notched numerous triumphs.

In all, Republicans must gain six seats to win a majority in the 100-member Senate in 2014, and can ill afford the sort of turmoil that led to unexpected defeats in Nevada, Colorado and Delaware in 2010 and in Missouri and Indiana last year.

In four of those races, tea party-based insurgents defeated establishment candidates for the party nomination, only to lose the general election. In Missouri, then-Rep. Todd Akin won his primary with an assist from Democrats, then lost in the fall after saying women's bodies were able to avoid pregnancy in cases of "legitimate rape."

The promising news for Republicans is that Democrats must defend 21 of the 35 Senate seats on the ballot next year. Alaska, Arkansas, Louisiana, Montana and North Carolina are among them, states that Obama lost and where incumbents will be seeking new terms.

Much of the early attention has focused on Iowa and Georgia.

Georgia last elected a Democrat to the Senate nearly two decades ago, and the party is in search of a top-rank contender. At the same time, officials claim renewed interest.

Among Republicans, Rep. Paul Broun has announced he will run, and Price and other members of the state's delegation are also considering candidacies.

All are conservatives, although Broun in particular has drawn attention for some of his remarks since coming to Congress five years ago.

He has said that evolution and the Big Bang theory are "lies straight from the pit of hell," and said before Obama took office he feared the then president-elect would establish a Gestapo-like security force to impose a Marxist dictatorship.

Broun's target voters are plain as he embarks on his statewide campaign. In a poke at potential primary challengers, his campaign website says that since 2007 the congressman has sponsored "more legislation to reduce federal spending that any other member of Congress from Georgia." It adds he has never voted to raise taxes or the government debt ceiling, never supported earmarks, opposed all bailout deals and authored a balanced budget amendment.

In Iowa, a political swing state, public opinion polls indicate Republican Rep. Tom Latham would be the stronger Republican candidate in a fall matchup with Rep. Bruce Braley, the only announced Democrat so far.

But early surveys also suggest a second Republican, Rep. Steve King has an advantage among potential primary voters.

Latham is a low-key congressional veteran, a close friend of Speaker John Boehner and the chairman of an Appropriations Committee panel that sets spending for transportation programs.

With an outspoken style, King is best known for his strenuous opposition to citizenship for illegal immigrants and his penchant for incendiary remarks.

Neither man has announced plans to run, but King has staked out his ground.

"I'm no stranger to outlandish attacks like this," he said in an emailed request for donations after officials with Rove's group cited some of his past comments as possibly problematic.

"Nobody can bully me out of running for the U.S. Senate, not even Karl Rove and his hefty war chest."